“Hooray for Hollywood, / That silly ballyhooey Hollywood, / Where every office boy and young mechanic / Can be a panic…”

Where do the starstruck come from, the eager hopefuls piling into Hollywood via trains, planes and automobiles? More important, how prepared are they to deal with what they encounter?

By the time Johnny Mercer penned the above lyrics in 1937, Hollywood had already been combing Broadway and vaudeville for its lineup of players for quite some time. For the promising new arrival, to sign a studio contract was to enter a hothouse world of special training in movement (sometimes including song and dance), elocution, carriage, wardrobe and whatever else it took to maintain a performance standard onscreen and — with the close-order presence of studio publicists — a cultivated image off. In a word, the actor was protected.

When the studio system began to break up in the 1950s, however, talent had no cover, nothing to help them navigate the riptides of career. The smart newbies took training before they made their move. You heard them talk about Sanford Meisner, Lee Strasberg, Stella Adler, the Actors Studio and other dojos that afforded them survival skills. Later they studied in university programs.

Cut to 2006, the age of the exalted amateur, the make-or-break weekend gross and 500 channels, where you can get face time onscreen for taffy-twisting a lyric, eating grubs for cash or parlaying a comedy routine into a cop sidekick role. Is this any incentive for a serious actor? And where do they come from?

“The money has pushed it in a different direction over the past 20 years,” says longtime acting coach Milton Katselas. “The desire for the craft of acting — the process, the voice, the body, the imagination — is less than the desire to hit the jackpot.”

“What is an actor now?” asks Todd Amorde, national director of member education for the Screen Actors Guild. “Some went to college and got their MFAs, some started out as kids, some get by on likable personas. It’s hard to pin down. On the one hand, the actor doesn’t always get to pick and choose. On the other, there’s a lot more to do, like voiceovers or hand modeling. Believe it or not, it takes a certain skill for a hand model to sustain a natural motion through 45 takes.”

Casting directors, whose reputations are based on sizing up actors beyond their 8x10s, see new arrivals coming out of the blue-chip universities and conservatories — but not as many as a decade or more ago. And perhaps unsurprisingly in our multiculti age, the pool is more international.

“I see actors coming out of the elite schools like NYU, Juilliard, Northwestern and Boston University,” says casting director Ronna Kress, whose credits include “Moulin Rouge” and “Pirates of the Caribbean: The Curse of the Black Pearl.” “But I’m not seeing the Laura Linneys or Billy Crudups of a decade ago. And we don’t have the training programs of England and Australia, where actors come out with hard experience.

“The process is much more global. What complicates it is that we’re constantly looking for the next new face, which always belongs to someone in their 20s who’s thrown into the marketplace without training at all. What most forget is that two-thirds of actors don’t make $5,000 a year, and only 1% of all the successful actors out there sustain a career.”

Adds casting director Jane Jenkins (“The Da Vinci Code,” “Cinderella Man”): “There are still actors coming out of Yale, Juilliard, UCLA, USC and a good program at SUNY Purchase. It’s still the route to take, even if it’s not as rigorous as the English system, where you need 300 hours of training before you can get a union card.

“There are a lot of crazy people who think they can take the short route and make it. Sometimes they’re right. None of it is formulaic. So much of it is serendipity — the right actor in the right movie is magic. But it’s a limited thing.

“Studios make a financial investment to bank on actors. Movies have become very expensive to make. You’ll want a Russell Crowe or Meryl Streep then. People who look at a screen and say, ‘I can do that’ often don’t realize that good acting only appears seamless and easy. But it isn’t. Talent only takes you so far.”

Nor is the MFA training ground uniformly helpful for the serious actor. Some have down cycles (Yale’s drama school has slipped in prestige recently). Some are better at teaching the difference between stage work and playing before a lens. What virtually none of them is good at, say casting pros, is preparing novices for what they need to know in the working world.

JoAnne DeNaut, casting director and artistic associate at Costa Mesa’s South Coast Repertory, likes what she sees of undergrads coming out of the North Carolina School of Actors, SUNY Purchase and Rutgers; and with MFAs out of NYU, UC San Diego, Juilliard and what she expects will be a resurgent Yale. What horrifies her, as it does most casting directors, is the near-complete lack of practical career advice the schools give their students.

“The kids come out not knowing how to market themselves, conduct business or structure their finances,” DeNaut says. “They don’t know what material to bring to an audition, how to dress or even how to engage with a casting agent.”

Literate, technically well-versed actors see all their training disappear as they’re thrown in with the inexorable stream of delusional wannabes pouring into Hollywood in search of overnight fame and a quick buck. The numbers are too staggering. (Keying in “casting actors” on Google draws 1.14 million entries).

The job therefore falls to SAG — a union that can offer its members no guarantee of a job — to provide a safe haven in a variety of programs, such as Liferaft and Casting Access, designed to give actors a real-world view of managing careers.

“Some actors walk into an audition looking sloppy, their hair undone, wearing flip-flops, completely unprepared to meet a casting director, as if all they had to do was show up,” says Marsha Smith, executive director of the SAG Foundation.

“The actor has to understand that he’s his own product. The rejection, the competition, the lack of money, the charlatans out there to exploit you — drama departments don’t teach you how to deal with that, or even how to create a resume.

“There’s a lot of heartbreak in this business, even with people who have one hit series, get the house and pool, and eventually lose everything. In the past I advised people to stay away. But acting is a passion. At least at SAG we can offer a library and screening room, an environment to network in, and a place where actors can come and not be ripped off